User getting Single Sign-On not enabled when trying to login, unable to login outside VDI

I have a user who is trying to login to the Sharefile application outside of his cloud desktop, and get's an error message saying "Single Sign-On Not Enabled For This Account." Hes' logged in while in VDI, but is unable to login outside VDI. No other user is having that issue, and the administrator has never instructed anyone to use SSO.